Improvement in nut-locks



UNITED STATES PATENT N OFFICE.

ABBAHAM C. HULL, OE ST. LOUIS, MISSOURI, AND .IOHN S. BROWN, OE MOUNT PLEASANT, DISTRICT OE COLUMBIA, ASSIGNOBS OE ONE-THIRD THEIB EIGHT To ISAAC H. STUBGEON, OE ST. LOUIS, MISSOURI.

IMPROVEMENT IN NUT-LOCKS.

`Specification forming part of Letters Patent No. 139,467, dated June 3, 18737; application J'led April 25, 1873.

To all whom it may concern:

lBe it known that we, AB RAHAM C. HULL, of

` i St. Louis, in the county of St. Louis and State `of Missouri, and JOHN Sy. BROWN, of Mount Pleasant, in the county of Washington and District of Columbia, have invented an 1mproved Screw-Bolt and Nut; and We do hereby f declare that the following is a full and exact description thereof, reference being had to the accompanying drawing making part ot' this Speciication, and representing an axial seeperiphery of an aperture which is partly cylindrical and partly somewhat conical, or Haring, substantially as and for the purposes hereinafter specified.

In the drawing, A represents a railroad screwbo1t split at d, as shown; and B, the nut fitting upon the screw-thread of the bolt, and having its screw-thread out in a cylindrical aperture for a portion, c, of its thickness, say one-half or more; and the remainder b of the aperture somewhat conical, or daring, as shown. The split d in the screw-bolt is cut to such a depth as to reach into the nut about as far as the Haring part d of the nut aperture reaches, when the nut is screwed upon the bolt asfar as it is required to go. The split is then opened, as shown in the drawing, by

driving a wedge therein, so that the screwthread will till the haring part of the nut. The nut B then cannot possiblywork ofi", but will rather tighten the more upon the bolt.

The advantages ot' the nut with partially tlaring screw-thread aperture in connection with the split screw-bolt are important: First. Since the bolt, when spread, has substantially a partially conical screw tting the partially much for Subsequent removal.

bolt may be shorteigsince a comparatively conical nut, there is an active tendency to tighten the nut and to resist its unscrewin g. Second. The screw is opened or spread with out' danger of breaking, since it begins to open inside of the nut, which resists its undue spreading and consequent Weakenin g. Third. There is no danger of spreading the bolt too Fourth. The

short projection beyond the nut suflices to enable it to be spread. Fifth. The nut can again be removed by simply turning it with a wrench, since the bolt being taper inside ot' the nut the latterv willride thereon and close the splitend thereof by a Wedge action; Whereas, if the spread ot' the bolt were entirely outside, the nut, with a cylindrical eye,`can have no Wedge-action to force itself oli.

This bolt is especially `valuable for railroads,V to attach the iish-plates or couplingsto the rails, since the nuts are completely locked upon -the bolts without the possibility of working to secure by Letters Patent, 4is

The combination of a split screw-bolt, A,

What we claim as our invention, and desire y 

